Automatic drain valve



FIG. 1 is a perspective view of an automatic drain valve showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The portions of FIGS. 1-7 shown in a coarse dot pattern and outlined in dashed lines are included for the purpose of illustrating portions of the automatic drain valve and form no part of the claimed design. 

CLAIM The ornamental design for an automatic drain valve, as shown and described. 